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Common benefits
Reducing the urban heat island effect
An Environment Canada study shows that if only 6% of the area occupied by the roofs of Toronto was green, the temperature of the city could fall by 1 to 2 ° C!
Stormwater retention
In summer, a green roof retains 50 to 100% of rainwater. Seen at the community level, the green roofs provide significant savings on water management and retain pollutants contained in those same waters that would otherwise runoff.
Improved air quality
Green roofs’ plants help improve the air quality by capturing airborne particles and pollutants on their leaves. Rainwater is then responsible for transporting those particles to the growing medium were they are later metabolised. Plants also filter out toxic gases and reduce the ambient temperature.
Improved biodiversity
Extensive green roofs, where man has little impact, are better protected and can become a haven for plants which are sensitive to trampling and bird species that nest on the ground or even some types of insects. One can even conceive a green roofs in order to imitate habitats or ecosystems lost or in peril. (For example: Grasslands of the American Midwest).
Energy saving
In summer, the soil and plants of a green roof protect the building against the sun's UV rays by absorbing the energy released by them. Due to the phenomenon of evapotranspiration, they can reduce heat gains thus helping to cool the area underneath and reduce air-conditioning needs of the building. In winter, the insulation provided by the growing medium helps to reduce heating energy needs.
Protecting and extending the life expectancy of the roofing membranes
Two main causes of deterioration of a conventional bitumen roof are ultra violet (UV) and fluctuations in temperature between night and day. The green roof protects the membranes from these two effects and thus prolongs the durability of roofs membranes which, in certain cases, can even be doubled!
Extensive green roofs which are primarily built for ecological purposes add marketing value to the building. In the case of roof gardens and patios that are also accessible, the gain is even greater because the roof adds a recreational area to the building.
Increased resistance to fire
Green roofs can delay the spread of a fire from the roof to the building, and vice versa, especially if the growing medium is saturated with water.
Acoustic insulation
Green roofs can be constructed to alleviate noise, the growing medium blocking low frequencies and the plants, high frequencies. According to tests conducted up to date, a growing medium with a depth of 12 cm (5 ") can reduce noise by 40 dB.
Still a new topic and technology in Quebec, green roofs have been installed for several hundred years in Europe. Since the emergence of knowledge in America in the years nineteen twenties, notably with the construction of the Rockefeller Center in New York, materials and technologies have been developed to meet a lot of architectural and environmental imperatives.

A green roof consists of a classic waterproofing roof membrane on top of which a variety of layers is installed. Those layers include different types of drainage and root barrier membranes, growing medium and plants. The picture below shows an accurate general sample of green roofs used in Quebec:

Toits verts au Québec
Certified installer
Les Toits Vertige are certified to install the technologies introduced in the "Products" section. Being certified installer of various technologies of green roofs, we can offer customers the guarantees offered by these manufacturers, thus ensuring the quality of services and installations.